15. The delivery of more than one child as a result of a single pregnancy and the adoption of more than one child at the same time shall be considered to be a single delivery and a single adoption for the purposes of this Act.
In the case of a delivery or adoption occurring while at least one of the parents is eligible for parental or adoption benefits for a previous event, the number of weeks of parental or adoption benefits is equal to the lesser of the following:
(1) the total number of weeks of parental or adoption benefits fixed under section 10 or 11;
(2) the number of weeks that have lapsed between the two events.
Lastly, benefits may not be paid concurrently to one person for more than one event.